Process for stabilizing dehydrated magnesium chloride against rehydration

Abstract

The present invention relates to a process for stabilizing dehydrated magnesium chloride by coating with a material having a high degree of affinity for water. The coating operation is preferably carried out with magnesium oxide in a layer thickness of at least 0.1 mm, the magnesium oxide being hydroxylated by adding water during the coating operation.

I claim: 
     
       1. A process for stabilizing dehydrated magnesium chloride against hydration, characterized by one of granulating and pelletizing the dehydrated magnesium chloride, providing the one of granulated and pelletized magnesium chloride with a coating of a material having a high degree of affinity for water, carrying out the coating operation using magnesium oxide, feeding the magnesium oxide into a granulator as a dry partially hydroxylated powder and completely hydroxylating the magnesium oxide during the granulation by adding water. 
     
     
       2. A process according to claim 1, characterized by granulating the magnesium oxide while adding water in an amount which exceeds the amount required for converting the magnesium oxide into magnesium hydroxide by up to a maximum of 30% by weight. 
     
     
       3. A process according to claim 1, characterized by granulating the magnesium oxide while adding water in an amount which exceeds the amount required for converting the magnesium oxide into magnesium hydroxide in an amount in the range of 10 to 20% by weight. 
     
     
       4. A process according to claims 1, 2 or 3, characterized by jointly feeding the magnesium chloride and the magnesium oxide into the granulator in the powdered form and granulating the magnesium chloride and magnesium oxide while continuously adding the amount of water required for the hydroxylation of the magnesium oxide and for the granulation. 
     
     
       5. A process according to claims 1, 2 or 3, characterized in that the coating is carried out in a layer thickness of at least 0.1 mm. 
     
     
       6. A process according to claim 1, 2 or 3, characterized in that the coating is carried out in a layer thickness in the range of 0.1 to 0.25 mm.